Fixed jaw car coupler



Jan. 2, 1968 w. J. METZGER 3,361,271

FIXED JAW CAR COUPLER Filed Feb. 7, 1966 5 Sheets-Sheet 1 INVENTOR WILLIAM J. METZGER Jan. 2, 1968 w METZ'GER 3,361,271

FIXED JAW'CAR COUPLER Filed Feb. 7, 1966 Q 5 Sheets-Sheet 2 F/QE INVENTOR WILLIAM J. METZGER Jan. 2, 1968 w. J.-METZGER FIXED JA W CAR COUPLER 5 Sheets-Sheet 5 Filed Feb. 7, 1966 UNCOUPLED {If I /0/7 INTERMEDIATE COUPLING STAGE INVENTOR WILLIAM J. METZGER Jan. 2, 1968 w. J. METZGER 3,36 ,2 v

FIXED JAW CAR COUPLER Filed Feb. 7, 1966 5 Sheets-Sheet 4 UNLOCKING COUPLED /04 EARLY STAGE A "TL V /4 F/G /2 F/G /3 UNLOCKING LA-EIE SIAG/E/ 7? LOCKSET g? ,IL 9 I \I 7 l I lljl I I C Z 45 g1; 98

I 41 a J3 v44 I Q5 1 2? (Q I /0 24 w Z H6 /4 F/G /5 INVENTOR WILLIAM J. METZGER Jan. 2, 1968 w. J. METZGEIR 3,361,271

FIXED JAW CAR COUPLER Filed Feb. 7, 1966 5 Sheets-Sheet 5 COUPLED INVERTED AND COUPLED 57-, 76 W "WU- INVENTOR. WILLIAM J. M ETZGER BY @WW United States Patent 3,361,271 FIXED JAW CAR COUPLER William J. Metzger, East Cleveland, Ohio, assignor to Midland-Ross Corporation, Cleveland, Ohio, 21 corporation of Ohio Filed Feb. 7, 1966, Ser. No. 525,539 12 Claims. (Cl. 213-100) This invention relates to railway car couplers of the fixed jaw or Willison type, and particularly to the species or sub-type thereof having operating parts which include a lock-set piece supported pivotally by the coupler head, a lock which tilts rearwardly within the coupler head to an unlocking position, and an anti-creep element pivotally supported by the lock and arranged relative to the lock-set piece to be positioned between oppositefacing abutments on the lock and the lock-set piece in preventing unwanted lock retraction. This latter feature distinguishes this species of coupler which is used in eastern Europe and commonly known as the 8A3 type coupler.

While the 8A3 type coupler has been proven to be reliable and durable throughout many years of service, it has been found deficient in several respects as to features presently desired in automatic couplers. For example, modern safety standards require that couplers remain coupled under severe combined endwise and vertical shock forces. Couplers must positively couple at high coupling speeds, they must uncouple while the cars on which they are mounted are in tensile relationship. When such couplers are used on hopper cars subjected to dumping by inverting the cars, it is essential that the couplers of inverted cars remain coupled. Under other conditions, cars in a string thereof are caused to separate automatically by previously setting the lock in retracted or lock-set condition. Since, through inadvertence or other reason, it is desirable to take a coupler out of lock-set condition to provide a more convenient arrangement than provided by the conventional 5A3 coupler. It is also desired under some circumstances to use a coupler of minimum bulk and especially of minimum vertical dimension.

Hence, an important object of this invention is to pro vide SA3 type couplers with anti-creep mechanism that effectively maintains the couplers in coupled relationship under exposure of the coupler to vertical, endwise, or combination vertical and endwise shock forces.

It is a further object to improve the coupling reliability of the 8A3 type coupler by constructing the lock thrower and the lock in a manner so as to limit the movement and rebound of the lock during rapid coupling action to an extent that still permits couplers to fully engage with recoil of the cars and couplers from coupled condition.

Another object is to provide the SA3 type coupler with convenient and readily accessible control for taking the coupler out of lock-set condition.

A further object is to provide the SA3 type coupler with more compact mechanism and a head for housing such mechanism of smaller external dimensions without reducing the strength of the coupler.

These and other objects are achieved in a coupler of the type wherein anti-creep action is effected in a known manner by an anti-creep element pivotally carried on the lock with a rear portion engageable with a portion of a forward-facing lock-set piece through improvements as follows:

(a) A rearward projecting arm of the anti-creep ele ment is correlated with a rear wall of the coupler head, an opening therein and a horizontal guide for the arm to the opening so that at certain positions of the lock, the arm will extend through the opening to be visible from outside the coupler and to indicate the operative condition of the coupler;

(b) The top wall of the coupler head, the anti-creep element, and the lock-set piece are correlated to prevent uncoupling of couplers when the cars are inverted as during roll-over or dumping operation, or in the case of bouncing of the internal parts of the coupler;

(c) The lock-throwing cam and the recess of the lock which receives such cam are arranged to provide a preliminary stop, i.e., engagement at the forward position of the cam permitting merely such movement of the lock rearward so that two opposed couplers may pass from uncoupled to coupled condition;

(d) The lock is related to the bottom Wall (especially at the point of pivotal connection therewith) and the rotor and a slot therefor in the lock are so related as to substantially restrict the look from movement toward the top wall of the coupler during car or coupler inversion;

(e) The lock is related to the bottom wall of the head to cause rocking first on one fulcrum and then on another in order to achieve rapid positive return of the lock to locking position;

(f) Projection of the coupler head below the coupler shank is cur-tailed to provide a coupler of unconventionally small height and to dispose the rotor shaft substantially in the lower third of the coupler cavity; and

(g) The lock-operating cam and the cam-following periphery of the recess of the lock therefor are so correlated as to provide high leverage or torque to the lock to ofiset the leverage of the rotor relative to the lock lost by close spacing of the rotor shaft and the pivotal connection of the lock in the lower third of the coupler cavity. The high-torque lock operating cam is further essential to uncoupling cars under relative tension, e.g., in the moment of beginning motion of a train.

In the drawing in respect to which this invention is described:

FIG. 1 is an exploded perspective view of a coupler showing the head in section and various internal components;

FIG. 2 includes plan and side elevation views of the coupler lock shown in FIG. 1;

FIG. 3 includes side elevation and rear end views of the thrower shown in FIG. 1 and normally carried on a shaft such as illustrated in FIG. 6;

FIG. 4 includes side elevation and end views of an anticreep element carried by the lock of FIG. 2

FIG. 5 depicts a lock-set piece in plan and side elevation views;

FIG. 6 is a longitudinal elevation of a rotor shaft which combines with the thrower of FIG. 3 to form the rotor of the coupler;

FIG. 7 is a cross section of the rotor shaft along lines VII-VII of FIG. 6;

FIG. 8 is a cross section of the rotor shaft along lines Vi'IIVIII of FIG. 6;

FIG. 9 is an elevation sectioned primarily to remove a side wall of the head and expose internal components of the coupler at uncoupled or pre-coupling condition;

FIGS. 10 and 11 are a fragmentary elevation in section and a fragmentary plan view, respectively, of two couplers at an intermediate stage of the coupling process;

FIGS. 12, 13, 14, 15, and 17 are fragmentary elevations of the coupler of the previous figures with a side wall removed in the manner of FIGS. 9 and 10, depicting the coupler components in various operating conditions as follows:

Coupled (FIG. 12);

Early stage of unlocking (FIG. 13);

Late stage of unlocking (FIG. 14);

Lock-set (FIG. 15); and

Coupled and inverted position (FIG. 17); and

FIG. 16 is a fragmentary front elevation of the coupler in coupled condition shown also in FIG. 12.

Although the coupler herein described is shown in FIG. 11 with wings that have complementary pockets and projections to interlock opposed couplers from relative vertical or lateral movement, the present invention is concerned with the coupler operating components housed within the coupler head and such features of the coupler head as contribute to the operation of these components. All figures of the drawing have reference to a single embodiment according to which the coupler A or B comprises -a head 5 providing a cavity, and as components received in the cavity, a lock 6, an anti-creep element 7, a lock-set piece 8, and a rotor 9 comprising a thrower 10 and a shaft 11.

The lock 6, at its normal position of rest in the precoupling condition (FIG. 9) or coupled condition (FIG. 12), rests on a bottom wall 14 of the head 5 with a front portion 15 of the lock adapted for engaging the corresponding portion of another lock, disposed forwardly of a transverse coupling plane 16 with reference to which a pair of coupled couplers are symmetrical. The lock 6, in this forwardmost coupled or pre-coupling position, relates to the head in this particular embodiment so as to extend to a level as low as the bottom wall 14; e.g., the undersurface of the lock 18 may be observed as lower than some areas of the undersurface of the wall 14.

For establishing pivotal connection of the lock with the head, the lock comprises a tooth 19, and the wall 14 has an opening 21 which receives the tooth. The pivotal connection of the lock and the head is of the two-fulcrum type wherein the lock pivots about a surface 23 throughout the front portion of the lock ambit and a surface 24 throughout a rear portion of the lock ambit. The rear bottom areas 25 and 26 of the lock cooperate with the surfaces 23 and 24, respectively, throughout a complete front to rear movement of the lock or vice versa. The purpose of the rear fulcrum, as defined by 24 and 26, is to increase the leverage applicable by the center of gravity of the lock in promoting more effective return of the lock to its forward position in FIGS. 9 and 12.

The lock 6 has a recess 27 of which its entire width is occupied by the thrower 10, and the entire width of the thrower is received by the recess except for a boss 29 which engages and assists the lockset piece in its functions.

The recess of lock 6 receives a substantial portion of the anti-creep element 7 and also has disposed therein a trunnion 31 based on a vertical surface 32. The trunnion extends through an opening 41 of the element 7 to provide pivotal support of the element. The surface 32 functions as a lateral or end-play bearing for the element 7 and is defined by a base or boss for the trunnion projecting from surface 35. The surface 32 shares a common vertical, longitudinal plane of the lock with another fiat surface 33 at about mid-depth of the recess. That is to say, the vertical plane of these surfaces divides the recess 27 into an inner half adjacent the surface 35 and an outer half adjacent the open side of the recess. In its movements relative to the lock, the anti-creep element 7 is confined by the surfaces 32 and 33 to a region in vertical alignment with the outer half of the rcess.

The anti-creep element 7, as shown in FIGS. 1 and 4, comprises a rearwardly extending arm 38 and a downwardly and rearwardly extending arm 39 which traverses the lock recess 27. The element 27 has an opening 41 which receives the entire length of the lock-supported trunnion 31 so that this trunnion does not extend into the space beyond the anti-creep element traversed by the lock-set piece 8. The arm 38 of the element has a transversely projecting lug 42 at its rear extremity which engages a guide shelf 44. As shown, the shelf 44- is an integral portion of the head 5 and extends forwardly from a rear wall 45 thereof. As shown in FIG. 16, the shelf 44 is attached to the side wall 46 in the background, and is spaced with respect to the side wall 47 of the head for freedom of movement of the rear portion of the lock-set piece therebetween.

The lock-set piece 8 is supported within the head on a trunnion 49 usually provided as an integral portion of the head 5. Essential features of the lock-set piece 8 include a front pad 51, a dihedrally-shaped rib 52 having a downwardly facing surface 53 and a rearwardly facing surface 54, a rear abutment 56 having a front facing surface 57 for engaging a rear end surface 58 of the anti-creep element 7, and a handle 59 projecting laterally from the body of the piece 8 in a direction opposite from that in which the abutment projects. The handle 59 extends through an opening 61 provided in the side wall 47 of the head. The opening 61 is of sufficient size to allow freedom of move ment of the piece 3 required in the operation of the couplers internal mechanism, or in such upward retraction of the lock-set piece necessary to take the mechanism out of lock-set condition. The handle 59 further has the function of limiting movement in the pre-coupling position of the piece 8 as the handle comes in contact with the lower extremity of the periphery of the side wall opening 61. Otherwise, the movements of the piece 8 are limited with regard to pivotal and vertical freedom by the oblong slot 63 which receives the trunnion 49.

Considered now the various portions of the rotor in a lateral direction from side wall 46 to side wall 47, the thrower has a lock-throwing cam 65 and a cam 66 for engaging and tilting the anti-creep element 7. These two cams form the body of the thrower. The thrower further includes the boss 29 which extends laterally from a side surface of the body, i.e., the cam 66, and engages and enables the lock-set piece to perform its lock-setting function. Additional features of the thrower 10 are a hub 68 defining a non-circular opening 69 for the shaft 11, and a rearwardly projecting lug 71 for engaging the underside of a rib 72 of the head.

The rib 72 extends forward from a rear portion of the head into close proximity with the hub 68. The purpose of the lug 71 in engaging the rib 72 is to prevent further downward movement of the thrower 10 from its forward coupled or pre-coupling position, as shown in FIGS. 12 and 9, respectively. Another important function of the rib 72 is serving as a support for the hub 68 when the coupler, e.g., is struck by another coupler under highspeed coupling conditions.

Another [feature unconventional to the SA3 type coupler mechanism is a preliminary stop for the lock for the purpose of making coupling more positive under abnormally rapid coupling conditions. To achieve this purpose, the thrower has a re-entrant surface 75, which is shown of dihedral conformation but may be concave or convex as well, arranged to engage a complementary front peripheral surface 77 of the lock recess 27. Engagement occurs at a stage of lock retraction slightly greater than that shown in FIG. 11. The function of surfaces 75 and 77 is to eliminate excessive rearward movement of the lock of two couplers during the act of coupling beyond that necessary for the locks to pass by each other. The greater lock movement permitted in conventional couplers of the SA3 type results in occasional failure to couple because of the tendency of the locks to bounce within the head and cause one or both to be out of locking position as the cars recoil and thus permit the couplers to part. Miscoupling is more likely to occur at high coupling speeds, i.e., at speeds above six miles per hour.

The rotor shaft 11 is of a design heretofore used in prior art coupling. The portion of its length indicated by numeral 80 is received in the head of the coupler and comprises journals 81 and 82 in bearing relation with bearings formed by the walls 46 and 47, respectively. A non-circular axle section 85 in contiguous intenposed relation with the journals 81, S2 is received in the complementary non-circular opening 69 of the thrower to enable the shaft 11 to transmit rotary motion to the thrower. The shaft 11 is secured from endwise movement by a bolt 87 which extends tangentially through an outboand bearing 88 of the coupler and tangentially through a groove 89 extending somewhat greater than 180 of the circumference of an outboard journal section 91 of the shaft 10, as shown in FIG. 8.

Considering the coupler now in its operative aspects and for purposes of description, beginning with the pre-coupling or uncoupled condition, as shown in FIG. 9, the coupler is observed with the lock 6 in its forwardmost descended position wherein it rests on the bottom Wall 14 of the coupler head. The lock is restricted from further forward movement by contact of the rotor shaft 11 with the rear extremity of the periphery of the opening 93 pro vided in the lock.

In FIG. 9, the anti-creep element 7 is shown with the log 12 thereof resting on the shelf 44. The lock set piece 8 is tilted forward as a result of its center of gravity being located rearwardly of its supporting trunnion 49. Its rear abutment 56 is thus positioned downwardly with respect to the rear extremity of the anti-creep element placing surfaces 57 and 58 out of engageable relationship. Because of this relationship, the lock 6 is free to move rearwardly within the cavity of the coupler head.

FIGS. 10 and 11 illustrate couplers A and B at an intermediate stage of coupling, wherein a pair of locks have engaged and pushed each other rearwardly in respective coupler heads to a point wherein they are in front face engagement and just about to pass out of this position into lateral juxtaposition as they complete the coupling operation. The lock-set piece pad 51 of each coupler has been pressed by the buffing jaw 95 of the opposing coupler back into the facial contour of each respective coupler. Hence, the lock-set piece 8 has been tilted rearwardly from its position in FIG. 9 to a position wherein the abutment 56 of the lock-set piece has moved upwardly underneath the rear portion of the anti-creep piece and has (raised it above the shelf 44.

FIG. 12 illustrates the coupler parts in the positions assumed at coupled condition of the coupler. The essential difference with respect to FIGS. 10 and 11 is that the coupler lock 6 is settled forward onto the bottom wall 14 and the rear extremity of the anti-creep element is now positioned on the shelf 44 in immediate forward juxtaposition with the abutment surface 57. The anti-creep mechanism is thus in operative position to prevent any rearward movement of the lock 6 beyond that permitted by engagement of the surfaces 57 and 58.

FIG. 13 illustrates coupler parts in positions assumed in consequence of about 20 of rotation of the rotor, i.e., the thrower 10 and the shaft 11, from the position shown in FIGS. 9, 10, and 12. Since the cam 65 of the thrower has not engaged the cam-follower surface 97 of the lock, the only other coupler part sustaining a shifted position is the anti-creep element 7 which has now been rotated to a position wherein its rear extremity is disposed above the abutment 56 of the lock-set piece. The coupler is thus in a condition for initiating rearward movement of the lock.

FIG. 14 shows the coupler at a late stage of unlocking wherein the thrower 10 has been rotated approximately 80 from the position of pre-coupling or con- 6 pled condition (FIGS. 9 and 12, respectively). Such movement has brought all three actuating portions of the thrower 10 into play. Cam 66 has remained in engagement with and continued to rotate the anti-creep element 7. The cam 65 has engaged the cam-following surface 97 of the lock and has tilted the lock backward through its first stage of fulcruming on surfaces 19 and 23 and into the second stage of fulcruming on surfaces 24 and 26. The boss 29 of the thrower 10 has engaged the downward facing surface 53 of the lock-set piece and lifted the piece to its highest elevation attained just before the boss 29 passes rearwardly from under the surface 53. It is to be noted also that the rear extremity of the anti-creep element has passed outwardly through an opening 98 in the rear wall 45 of the coupler head. Optionally, a door 99 is provided which will usually be closed during the use of the coupler to restrict the entrance of dirt and moisture interiorly of the coupler. As shown, the door 99 is engaged and opened as a rearward portion of the anti-creep element passes through the opening 98.

FIG. 15 shows the coupler in lock-set condition. Such condition is contingent upon engagement of the pad 51 of the lock-set piece by the bufiing jaw of the opposed coupler. As long as the lock-set piece is retained by the opposed coupler in the position shown, and since the thrower It) must return to a forward position, e.g., that of FIGS. 9, 10, and 12, to allow the lock to drop forward, lock-set condition is established by:

(1) Lodgment of the boss 29 against the rearward facing surface 54 of the lock-set piece, and

(2) Retention of the lock rearwardly by engagement of the thrower surface 65 with the cam following surface 97 of the lock.

Lock-set condition is intentionally indicated by extension of the rear portion of the anti-creep element 7 through the opening 98. Such indication is further enhanced by the open position of the door 99. The opened door and the exposed portion of the anti-creep element are also useful in indicating a fully retracted position of the lock attained by external manipulation of the rotor shaft.

Use of couplers such as the type herein described entails operation under conditions in which a pair of coupled couplers are inverted and maintain coupled relationship.

FIG. 17 illustrates the positions of the coupler components assumed during inversion. It is believed that this figure also illustrates a condition that the coupler may assume when upright but in a state of vertical shock. The function of the structure brought into play as illustrated by FIG. 17 is to prevent the lock 6 from working out of its frontward or looking position during inversion. It is essential that, at inverted position, the lock does not undergo such movement toward its top wall 101 so as to permit it to become unhinged in respect to the bottom wall 14 through disengagement therefrom of the tooth 19.

Lock movement of this nature is prevented by engagement of the lock with the shaft 11 along the lower ex tremity of the periphery of the lock opening 63 at a point approximately indicated by the numeral 102. It has been observed that the anti-creep element does not maintain abutting relationship with the abutment surface 57 and that the anti-creep piece and the element 7 cannot be relied upon to maintain the forward position of the lock in the inverted position of the coupler. Both the piece and the element have their centers of gravity disposed rearwardly of respective pivots. Hence, the rearward portions of both parts tend to position toward or against the top of wall 101 during inversion.

To prevent rearward passage of the rear extremity of the anti-creep element 7 past the upper surface 103 of the lock-set piece and thence outwardly through the opening 93, the underside of the coupler wall 191 is provided with a saw-tooth shape lug 104 having a front-facing surface 105 adapted for engaging the rear end surface 53 of the element 7. Thus, surface 1% constitutes an alternate abutment which assumes the function of abutment surface 57 under conditions in which the surface 57 may not serve. As the coupler is rotated from the position shown in FIG. 17, the components thereof assume the position shown in FIG. 12.

The coupler described above, while retaining many general features which contributed to the durability of the conventional SA3 type coupler, especially the anticreep feature, incorporates anti-creep mechanism which is intended to operate more positively and provide more protection against uncoupling during intended or unintended inversion of vehicles. The present coupler also provides preliminary stop lock and thrower construction intended to make coupling more positive at all coupling speeds. The rotor shaft is protected against excessive force in lateral relation with its axis not found in the conventional SA3 type. More compactness, especially in respect to height and horizontal length, is achieved now in the present coupler over the predecessor type. Convenience in taking the coupler out of lock-set condition and the mechanism for indicating the condition of the coupler are further advantages of the present coupler.

The terms and expressions which have been employed are used as terms of description and not of limitation and there is no intention of excluding such equivalents of the invention described or of the portions thereof as fall within the purview of the claims.

What is claimed is:

1. In a fixed jaw coupler comprising:

a head having a cavity, a lock housed in said cavity having a lower rearward portion in pivotal connection with a lower rearward portion of the head, a lock-set piece pivotally supported by the head in lateral juxtaposition with the lock, said lock-set piece providing a forward-facing abutment, an anti-creep element pivotally supported by the lock in lateral juxtaposition therewith, said element having a rearward projecting arm positioned in front of, and engageable with, said abutment at positions of said components corresponding to coupled condition of the coupler, and a rotor having cam means for engaging the lock, the piece, and the element in a desired sequence as the rotor tilts the lock rearward to an unlocking position;

said head having a rear transverse wall and an opening therethrough disposed at a level approximately that of said arm, and guide means disposed forwardly of the opening for guiding said arm toward and through said opening;

said arm having a length disposing its rear extremity in positions ranging from engagement with said guide means to outward of said opening as said lock moves rearwardly from coupling position to uncoupling position.

2. In a coupler according to claim 1 wherein:

said guide means is a shelf contiguous with said wall and has an upper surface in forward longitudinal alignment with said opening, and said abutment is defined by a rear portion of said lock-set piece extending laterally into longitudinal rearward alignment with said arm and transverse juxtaposition with said shelf.

3. In a coupler according to claim 2 comprising:

an outwardly opening closure movably mounted on said rear wall for normally closing said opening and yielding to said arm during movements thereof through the opening.

4. In a coupler according to claim 1 wherein:

said rotor comprises a shaft interlocking with said cam means against relative rotation and said lock has a slot receiving said shaft in all positions of the lock relative to the shaft, the periphery of said slot underneath said shaft extending at close clearance therewith;

said connection of the lock and head comprising a downward projecting tooth and an opening in said head disposed generally under said shaft; and

said head has a top wall and an undersurface thereof defining a forward-facing stop disposed just outside the radius of a rearward-facing end surface of said arm with respect to its center of rotation on said lock, said arm being engageable with said step upon inversion of the coupler in coupled condition.

5. In a coupler according to ciaim 1 wherein:

the lock has a recess extending inwardly from one side to accommodate said cam means;

said element comprises a downward extending arm received in the outer half of said recess; and

said cam means comprises:

(1) a first cam disposed along the inner half of the recess for actuating the lock, said cam and recess being disposed essentially forwardly relative to the axis of the rotor at locking condition of the coupler, and

(2) a second cam disposed in the outer half of the recess relative to the first cam so as to engage and move said downward arm rearwardly and said rearward arm upwardly out of opposed relation with said abutment during rotor rotation before actuation of the lock.

6. In a coupler according to claim 5 wherein:

both arms of the element have a common longitudinal plane; and

said lock comprises a trunnion of horizontal axis based at the inner side of said recess for supporting the element, and

said trunnion has an annular thrust-bearing surface for the element at the dividing plane of said recess halves.

7. In a coupler according to claim 5 wherein:

the peripheries of the lock recess and the first cam define protruding and reentrant surfaces arranged to engage in complementary relationship at partial retraction of the lock from its coupler-locking position with the rotor remaining at its coupler-locking position.

8. In a coupler according to claim 5 wherein? said cam means has a hub portion and said rear Wall has an integral extension extending into close clearance with the hub portion at the rear of the cam means.

9. In a coupler according to claim 8 wherein:

said hub portion comprises a lug for engaging the under side of said extension at a coupler-locking position of the rotor disposing said first cam directly forward of its axis of rotation.

10. In a coupler according to claim 5 wherein:

said downward extending arm and both cams are received within said recess and said lock-set piece is supported in loosely sliding relation with the lock along the open side of the recess;

said lock-set piece comprises a ledge disposed forwardly of the rotor axis defining a downward facing surface and a rearward facing surface; and

said cam means comprises a boss fixed to and extending laterally from the second cam in underneath spaced relation with said ledge, and said boss is spaced with respect to the rotor axis to engage said ledge and lift said lock-set piece during coupler-unlocking movement of the rotor;

said boss becoming lodged against said rear facing ledge surface at release of the rotor at completion of said unlocking movement.

11. In a coupler according to claim 10 wherein:

the coupler head has a side wall in juxtaposition with the side of the lock-set piece which faces away from the lock;

9 10 said lock-set piece has a handle projecting transversely the rotor shaft is disposed within the lower third of the through said side wall; and cavity height, said side wall has an opening accommodating the handle throughout the full range of movement of the References Cited lock-set piece incidental to coupler operation and an 5 UNITED STATES PATENTS upward movement thereof to disengage said boss when lodged against said rearward facing ledge sur- 3283917 11/1966 Dufourmantel 213'' 10O face. 1 d l h FOREIGN PATENTS 12. In a coup er accor ing to c aim 5 w erein: the bottom wall of the head extends in the longitudinal 1181260 12/1964 Germany 10 dlrectlon generally honzontally with its undersurface I at a level approximately that of the lower front ex- ARTHUR LA POINT H y Examme" tremity of the lock; and D. E. HOFFMAN, Examiner. 

1. IN A FIXED COUPLER COMPRISING: A HEAD HAVING A CAVITY, A LOCK HOUSED IN SAID CAVITY HAVING A LOWER REARWARD PORTION IN PIVOTAL CONNECTION WITH A LOWER REARWARD PORTION OF THE HEAD, A LOCK-SET PIECE PIVOTALLY SUPPORTED BY THE HEAD IN LATERAL JUXTAPOSITION WITH THE LOCK, SAID LOCK-SET PIECE PROVIDING A FORWARD-FACING ABUTMENT, AN ANTI-CREEP ELEMENT PIVOTALLY SUPPORTED BY THE LOCK IN LATERAL JUXTAPOSITION THEREWITH, SAID ELEMENT HAVING A REARWARD PROJECTING ARM POSITIONED IN FRONT OF, AND ENGAGEABLE WITH, SAID ABUTMENT AT POSITIONS OF SAID COMPONENTS CORRESPONDING TO COUPLED CONDITION OF THE COUPLER, AND A ROTOR HAVING CAM MEANS FOR ENGAGING THE LOCK, THE PIECE, AND THE ELEMENT IN A DESIRED SEQUENCE AS THE ROTOR TILTS THE LOCK REARWARD TO AN UNLOCKING POSITION; SAID HEAD HAVING A REAR TRANSVERSE WALL AND AN OPENING THERETHROUGH DISPOSED AT A LEVEL APPROXIMATELY THAT OF SAID ARM, AND GUIDE MEANS DISPOSED FORWARDLY OF THE OPENING FOR GUIDING SAID ARM TOWARD AND THROUGH SAID OPENING; SAID ARM HAVING A LENGTH DISPOSING ITS REAR EXTREMITY IN POSITIONS RANGING FROM ENGAGEMENT WITH SAID GUIDE MEANS TO OUTWARD OF SAID OPENING AS SAID LOCK MOVES REARWARDLY FROM COUPLING POSITION TO UNCOUPLING POSITION. 